A long-term in situ calibration system for chemistry analysis of seawater  

作　　者：Chun-yang TAN Bo JIN Kang DING William E. SEYFRIED Jr. Ying CHEN 

机构地区：[1]State Key Lab of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027, China [2]Department of Geology and Geophysics, University of Minnesota, Minneapolis 55455, USA

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2010年第9期701-708,共8页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：Project supported by National Natural Science Foundation of China (No. 40637037);the National High-Tech Research and Development Program (863) of China (No. 2007AA091901);the National Science Foundation of U.S. (No. 0525907);the China Scholarship Council (No. 2009632124)

摘　　要：An in situ calibration system is a versatile exploration instrument for electrochemical sensors investigating the biochemical properties of the marine environment. The purpose of this paper is to describe the design of an auto-calibrating system for electrochemical (pH) sensors, which permits two-point in situ calibration, suitable for long-term measurement in deep sea aqueous environments. Holding multiple sensors, the instrument is designed to perform long-term measurements and in situ calibrations at abyssal depth (up to 4000 m). The instrument is composed of a compact fluid control system which is pressure-equilibrated and designed for deep-sea operation. In situ calibration capability plays a key role in the quality and reproducibility of the data. This paper focuses on methods for extending the lifetime of the instrument, considering the fluidics design, mechanical design, and low-power consumption of the electronics controller. The instrument can last 46 d under normal operating conditions, fulfilling the need for long-term operation. Data concerning pH measured during the KNOX18RR cruise (Mid-Atlantic Ridge, July-August, 2008) illustrate the desirable properties of the instrument. Combined with different electrodes (pH, H2, H2S, etc.), it should be of great utility for the study of deep ocean environments, including water column and diffuse-flow hydrothermal fluids.An in situ calibration system is a versatile exploration instrument for electrochemical sensors investigating the biochemical properties of the marine environment. The purpose of this paper is to describe the design of an auto-calibrating system for electrochemical （pH） sensors, which permits two-point in situ calibration, suitable for long-term measurement in deep sea aqueous environments. Holding multiple sensors, the instrument is designed to perform long-term measurements and in situ calibrations at abyssal depth （up to 4000 m）. The instrument is composed of a compact fluid control system which is pressure-equilibrated and designed for deep-sea operation. In situ calibration capability plays a key role in the quality and reproducibility of the data. This paper focuses on methods for extending the lifetime of the instrument, considering the fluidics design, mechanical design, and low-power consumption of the electronics controller. The instrument can last 46 d under normal operating conditions, fulfilling the need for long-term operation. Data concerning pH measured during the KNOX18RR cruise （Mid-Atlantic Ridge, July-August, 2008） illustrate the desirable properties of the instrument. Combined with different electrodes （pH, H2, H2S, etc.）, it should be of great utility for the study of deep ocean environments, including water column and diffuse-flow hydrothermal fluids.

关 键 词：PH LONG-TERM In situ calibration Flow control Low power 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] O65[自动化与计算机技术—控制科学与工程]